KYIV — Ukraine’s popular former Defense Minister Mykhailo Fedorov has emerged as a new rival to President Volodymyr Zelenskyy — but his call for an election is facing immediate blowback.

In a video address on Tuesday night, he zeroed in on topics he knew would strike a public chord in one of the most direct internal challenges to Zelenskyy since Russia’s full-scale invasion of Ukraine. He complained that corruption was undermining the war effort and protested about centralized and opaque decision-making in the Zelenskyy administration — for which he worked until only last month.

However, Fedorov’s unexpected appeal for the nation to go to the ballot box sparked immediate retorts across the political spectrum. Critics insisted such an election would be banned by Ukraine’s martial law, would be impossible to organize in wartime, would play into Russia’s hands and would sow division when national unity remains vital.